To determine the relationship between vascular beta-amyloid (beta A4) and senile plaques (SPs) and neurofibrillary tangles (NFTs). We counted vascular amyloid deposition with SP and NFT density in the medial temporal lobe (CA1 plus the subiculum) and the cerebellum. The brains of seven patients with Alzheimer's disease and of three age-matched nondemented control subjects were studied. In Alzheimer's disease, the density of beta A4-laden blood vessels was significantly higher in the cerebellum than in CA1 plus the subiculum. Conversely, the densities of SPs and NFTs were much greater in the CA1 plus the subiculum than in the cerebellum. This study indicates that local vascular beta A4 deposition is not directly correlated with SP and NFT densities. Deposition of beta A4 in blood vessel walls may not be instrumental in the formation of SPs and/or NFTs in the brain.